Shock absorber



C. H. BROWN.

SHOCK ABSORBER.

APPucATloN FILED oc. 24. 1921.

1,425,834; y vnummern-ug.15,1922.

3 SHEETS-SHEET 1.

lllllllll CfH. BRDWN. SHOCK ABSORBER. APPucATroN FILEn'bcT. 24, 1921.

1,425,834. l PatentedAug.`15,192z.

s SHEETS-SHEET s.

HARLES H'. BROW1\T, 0F INI-DIANAPOLIS, INDIANA.

' sHociz. ABsonBEn.

'State of indiana, have invented new and useful Improvements in Shock Absorbers, of which the following is a specification.

This invention relates to a buffer or shock absorber for the suspension of motor or` other vehicles of the type in which a piston moves within a cylinder filled with liquid and forces the liquid through a by-pass from one side of the piston to the other, the bypass being regulated to vary the resistance of the liquid to the -piston by means of a p valve therein.

An object of the invention is to provide. a shock absorber of the type above described, as distinguished from the friction type of absorber, which has substantially all of the advantages of the improved friction type absorber without t-he complicated structure and limited durability of the buffer which seeks to provide a fluid resistance absorber.

depends upon friction. for its shock absorbing power. More specifically, the invention which will afford practically no resistance to the action of the vehicle springs as the vbody moves downwardly until thebody is extremely close to the axle and there is danger of the axlebeing struck, whereupon the absorber provides a relatively quick and severe checking action. ln other words, the

shock absorber of this invention permits free functioning of the vehicle springs during the initial stages of the downward body movegradual but positive resistance to the recoil ofthe springs except during the initial stage of the return'movement if the absorber has applied a checking'action to prevent striking of the axle when the body has moved. downwardly. '.lf the downward movement" of the oody has not caused the labsorber toV apply the severe and quick resistance above mentioned thejupward movement is checked by the absorber during'every stage, including the initial stage.

Other objects of the invention reside in the general construction of the absorber and Speciication of Letters Patent. Patterned Aug, Application filed October 2.4, 1921. Serial No. 509,799. i

i5, ieee.

the arrangement of its' several parts, andl have, generally, to do with simplicity, silent and elicient operation and manufacturing economy. The above objects of the invention, vand others of a similar nature will become obvious as the. description proceeds, there. being shown in the accompanying drawings one form of a device in which the invention may be embodied.

. ln the drawings Fig. l is an elevationalview absorber appliedto a vehicle,

F1g. 2 is an elevational view of the absorber,`

F 3 is a sectional view of the fluid conshowing the taining cylinder on the line 3`-.3 of Fig. 2.v

Eigx is a horizontal section on the line of Fig,l Fig. 5 is a face view of the piston, Fig. 6 is a sectional View of the piston on the line 6-6 of Fig. 5,A f F ig. 7 is an elevational View of the piston operating cam, I i l Fig. 8 is an end view showing the face of the cam, and f F ig. 9 is a diagrammatic view showing the relation of the cams upon. thepiston and the piston operating disk.

Referring to the drawings for a more detailed description, 10 indicates a cylinder .v which may be secured to the chassis C, as

by means of bolts 11 passing through ears l2 upon the fluid containing cylinder intothe chassis frame. Within the cylinder is positioned a piston 13 (Figs. 5v and 6.). formed upon its upper face with an annular cam portion 14 and providedwith a plurality of spaced marginal openings 15 through which pass guide pins in the form of bolts 16. The bolts 16 are provided with enlarged heads 17 seated withinsockets in one end wall ofthe cylinder and extending' 21, this port serving to permit the. intro-1"' duction or resistance fluid into the cylin- 'der without removingthe cylinder cap.

' 'lhepins 16 serve 'fto guidel the piston, l which has a rectilinear movement within the cylinder, and function to prevent rotation of the piston; One of the studs 22 (Fig. 3)

' 25 below and above the piston, respectively,

and the' passage is controlled by a needle valve 26 threaded into a counter-bore at the upper end ol tlie bolt. 'lhe valve has a i seat, as will be noted, just below the lateral ports 25, and thus regulates the passage of duid' upwardly through the central bore which serves as a by-pass for the Huid placed durin the movement of the piston in the direction of the closed end of the cylinder. The piston may be normally maintained in the position shown in Fig. 3 by a plurality of coil springs 27 abutting the closed end of the cylinder and the rear face of the piston, bosses 28 upon the piston serving to maintain the springs against displacement.

In order to permit the return of iluid, which has been forced through lthe by-pass 23, without resistance. to the movement of the piston back to its normal position, shown in Fig'. 3, the piston is provided with a central port 29; and a one-way valve 30 having a sliding movement lupon a stud v31 formed upon an operating cam y32 is nrmallypositioned with a peripheral Harige 33 closing the port, a spring 34 holding the valve in this position. This spring is considerably lighter than the piston return springsl` 27, and any fluid which has been forced through the oy-pass to the opposite side or the'piston from the springs 27 will pass through the port 29 to the main body of the Huid as the piston is returned by the springs 27.

lin order to permit the vehicle springs'to function freely the piston should preferably -be operated by means which will not operate the same and force any of the fluid through -the ley-pass during the initial stages of the downward vehicle body movement. How-l ever, it is desirable that the Vabsorber check the downward movement of the body during its latter stages, or, in other words, as the bodyapproaches the axle, in order to prevent striking of the axle. Moreover, the piston operating means should function during the upward movement of the body under the recoil of the springs so as to prevent the body frombeing thrown upwardly by the springs beyond its normal riding position.y The checking action of the absorber during the return should preferably be a.' radual one, while its resistance during the atter stages of the downward'body movement must necessarily be a quick, rather severe and positiveaction.

The cam disk 32 has, upon its under face,

a plurality of cams which cooperate with the camslfl: 'upon the'face of the piston.

" The* disk is held imposition by the stud 31,

Ies

which has a bearing in a socket 31 .in thel end 'wall ci the cylinder, and by a second integral stud 35 which extends through the closing cap 18 to the exterior of the cylinder,

i ineaeee `a washer 36 being placed between the disk and the cap 18 Ato prevent leakage. Upon the outer squared end (F ig. 2) of the stud 35 is fixedly clamped an arm 37 which may be connected by means of a link 38 and U- clip 39 to the vehicle spring S. Obviously, upward and downward body movement will result in rotation of the cam disk and its studs, the disk studs having bearings in the cylinder closing cap and end wall. The ormation of the cam 14 upon the piston and the operating cam 32 is more clearly shown in Fig. 9, wherein is also illustrated the relative normal relation of the piston and operatin'g cams. Referring to the construction of the piston cam 14 it will be noted that the lsame is formed with a pair of spaced high 41, one meeting point being shown at 43 in the development of the cam illustrated in F ig. 9.

The operating cam 32 is formed in substantially the same manneras the piston cam, and has high points 44, gradually inclined surfaces. 45, and rather sharply inclined surfaces 46 meeting the sharply inclined surfaces at points 47.

, When the body of the vehicle is in normal positionthe cams are in their relative positions shown in Fig. 9 with the inclined surfaces of the operating cam 32 substantially 10G half way by the gradually inclined surfaces 42 of the piston cam, and downward movement of the body results in rotation of the operating cam disk in the direction of the larrows shown in Fig. 9. During the initial stages of this downward movement the high points 44 of the operating cam are receding from the high points 40 of the piston cam, and the springs 27 are forcing the piston away from the body of fluid behind the piston, any fluid above the piston passing through the port 29 during this movement. Until the graduallv inclined surfaces of the Y two cams are in absolute registry and the high points 44 of the operating cam have 115 reached the low points 43 o'f the piston cam the absorber oi'l'ers no resistance to the downward body movement, and the vehicle springs function reelv At this stage of 'the body movement the springs are usually 120 ton and forced through the by-pass 23 to the opposite side of the piston. The resistance which the fluid offers to this movement may be variedby adjusting the needle valve 26 in the by-pss, and this may be readily done since it will be noted that the valve is accessible without opening the cylinder.

Upward movement of the body results in rotation of the operating cam disk in the opposite direction from that indicated by the arrows; and if the checking cam surfaces 41, 46 have been called into play during the downward body movement there is no resistance to the upward movement until the high lpoints 44 of the operating cam reach the low points 43 at the lower extremities of the gradually inclined surfaces 42 of the piston cam. It should be borne in mind that any fluid whichmay have been forced through the by-pass during the downward body movement has, by this time, y returned through the port 29 to the main body of' fluid behind the piston, the return taking place'while the piston is returning to its normal position under the influence of the springs 27, which it does while the high points 44 of the operating cam .are approaching the low points 43 of the piston camlduring the initial stages of Ithe upward body movement. Continuation of the upward body movement results in the gradually inclined surfaces 45 of the operating cam moving upwardly along the gradually inclined surfaces 42 of the piston cam,v and the piston is .'thus gradually and slowly moved against the body of liquid to force the same through the by-pass to the opposite side of the piston.

It is thought that the operation of this device will be entirely clear from the above description, and that it will be appreci'ated that the use of this -device permits the'use of more flexible vehicle springs, since it positively prevents the. clash of the frame and axle when the vehicle is over-loaded. It is highlydesirable, upon motor vehicles, to employ rather fleXiblespri-n'gs, but when such springs are used there is always the\ danger of the frame and axlestrikingwhen the vehicle isy overloaded, or when the4 vehicle is traveling over rather rough, roads.

Attention'is also called to the absolute freedom of`vehicle 'spring action which this absorber affords. while 'at the same timel protecting the vehicle in the-manner above setf,

forth.- i It shouldvbe understood that numerous lmodifications may be made in the structure illustrated and described, the above detailed disclosure being merely illustrativel and in no sense restrictive of the invention.

I claim: n

1. In a shock absorber of the class de-A scribed, the combination of a fluid contain- ,ing cylinder," a reciprocable piston in the lby-pass 2. In a shock absorberl of 'the class' de- `scribed, the combination of-a fluid containing cylinder, a non-rotatable rectilinearly movable piston in the cylinder, a rotatable cam member for moving said piston, and a permitting. displacement of the fluid from one side to the other of said piston.

- 3. In a shock absorber, the combination of a fluid containing cylinder, a piston in the cylinder, fand'movable means for actuating said piston to displace the fluid, said means not functioning to move the piston and to displace the fluid during the initialstages of its movement in one direction.

sov

4. In a shock absorber, the combination of a fluid containing cylinder, a piston in the cylinder, andmovable means for actuating said piston to displace the fluid, said meansnot-functioning to move the piston and to displace the fluid during the initial stages of its movement in one direction, but operative to produce relatively quick piston actuation during a continuation' of its movement in the same direction.

5. In a shock absorber, the combination` ofa fluid containing cylinder, a piston in the cylinder, and movable means for actuating said piston to displace the fluid, said 'means ,not functioning to move thepiston and to displace the fluid during the *initial stages of its movement in, one direction, but operative to produce relatively quick piston actuation during a continuation ofits movement inV the same direction and effectiveto lproduce, piston movement and fluid displacement during its movement in the oppositedirection.

6, In a shock absorber, the combination of a fluid containing cylinder, apiston in the cylinder, and movable means for 1acuating said piston to displace the fluid, said means not functioning to move the piston` and to displace the fluid during the initial stages4 of its movement in `one direction,

but 'operative to produce .relatively quickv 'y piston actuation during a continuation of its 'movement yin` the same direction and effec't'iveto producemelatively gradual piston movement and l fluid displacement in then -samedirection during its movement in they opposite directionsv x 7. In a shock absorber of the class described,:the A combination of a fluid containing cylinder, arectilinearly movable piston in the cylinder adapted to displacethe=fluid` therein, a cam disk in the cylinder for moving the piston, complementary .cam means associated with saidlpiston, the cams being effective upon relative rotation of the diskV 8. In a shock absorber of the class described, the combination of a fluid containingv cylinder', a rectilinearly movable piston in the cylinder adapted to displace the fluid therein, a cam disk in the cylinder for moving the piston, complementary' cam means associated with said piston, the cams being effective upon relative rotation of the disk and piston in one direction to produce op, eration of the piston and fluid displacement only after the initial stages of the movement, the piston operation being. then relatively quick.

9. ln a shock absorber of the class described, the combination of a fluid containing cylinder, a rectilinearly movable piston in the cylinder adapted to displace the fluid therein, a'cam disk in the cylinder for moving the piston, complementary cam means associated With said piston, the cams being effective upon relative rotation of the disk and piston in one'direction to produce operation of the piston and fluid displacement` only after the initial stages of the movement, the piston operation being then relatively quick, and during relative rotation in the opposite direction being effective to produce relatively gradual piston movement and ,fluid displacement.

10. A shock absorber of the class described comprising a Huid containing cylinder, a piston vinv said cylinder, cam means for moving said piston lto displace the fluid from `lone side to theother of said piston, a bypass in said cylinder to permit displacement of the fluid upon actuation of the piston, means for regulating the size of said by-pass to varyl the fluid'resistance, means `.for returning said piston to a normal position,'and a one-Way valve permitting return Y of said fluid `Without.resistance to return l1. A shock absorberof the class'described comprising a--fluid containing cylinder, a. piston in the cylinder having a rectilinear movement, means for guiding said piston and preventing rotation thereof, said means comprising a plurality oit-studs extending through the piston adjacent the Wall of the cylinder, one of said studs havingv a central bore provided with an inlet on one side'of said piston 'and an outlet on the other side ving a earin `end Wall of t. e cylinder,and a' second stud extending :through said piston having a of thepistcn, and a rotatable cam for moving said piston.

l2. A shock absorber of the class described comprising a fluid containing cylinder, a piston in the cylinder having a rectilinear movement, means for guiding said piston and preventing rotation thereof, said means comprising a plurality of studs extending through the piston adjacent the Wall of the cylinder, one of said stud's having a central bore provided with an inlet on one side of said piston and an outlet on the other side of the piston, said piston having a port therein permitting return of the fl'uid'which has been for'ced through said by-pass, a oneable lvalve in said by-pass .for varying the resistance of the fluid, and a rotatable earnv -rotatable cam disk 1n the cylinder, complementary cams on said piston, said disk having .a bearing stud extending through an end Wall of the cylinder, and a second stud vWay valve controlling said port, an 'adjustextending through said piston having a bearing in the opposite end Wall of the cylinder, an adjustable valve for regulating said by-pass, said piston having a port therein to permit the return of fluid displaced by the piston, and a one-Way valve controlling said port.

14. A shock absorber of the class described comprising a fluid containing cylinder, a piston in said cylinder, guide studs in the `cylinder' for said piston preventing rotation of the piston, one'ofsaid 'studs having a central bore servin as a fluid by-pass, a rotatable canrrdiskl 1n the cylinder, complementar cams lon said piston, said diskhavstud A'extending through an said secondstud and controlling said port.-

' ln testimonywhereof l have hereunto set myl hand.

ci-matas n. BRcWN. 

